system consists of radar, an electro-optical deterrent and
sonar designed for the long-distance detection of swimmers and divers and their subsequent engagement.

“The second prototype has been given to the Navy
for some testing and, later, we’ll modify the software
based on the Navy’s feedback,” Meisinger said.

One attraction of the HiRSA software package is that it
is easy to learn. Meisinger said that today’s young Sailors,
Marines, Coast Guardsmen, Soldiers and Airmen “are so
computer literate that we could have them up and running with eight hours of training. We’ve actually turned
Sailors loose on the system with two hours of training and
they really didn’t have too many issues with it.”

21CSI, like many of the companies involved in
diver- and swimmer-defense systems, believes that
concerns over port and harbor security could have an
important effect on their business.

“Our coastlines are probably [among] the most
risky and vulnerable points because we don’t have a lot
of security out there,” Meisinger said.

Another such company is Sonardyne International
Ltd., Yateley, England, which produces the Sentinel
Intruder Detection Sonar that the company promotes as
a “third-generation Intruder Detection Sonar designed to
counter the threat of underwater attacks against ships,
harbors, coastal installations and offshore oil platforms.”

The U.S. Navy’s Integrated Swimmer Defense
System also incorporates Sonardyne’s Sentinel.

One of the attractions of Sentinel is its compact size.
The sonar head used for diver detection is 12 inches in
diameter, 17 inches high and weighs 77 pounds. This
compact sonar head can provide 360-degree coverage
across a 0.9-nautical-mile radius. The size of the system
makes it highly portable.

Sonardyne notes in its product literature that many of
the world’s harbor facilities already have robust terrestrial defense systems such as close-circuit television and
perimeter fences, but a diver defense system like Sentinel
will deny another possible avenue of approach.

Sentinel also can track hundreds of targets simultaneously; an important consideration in a port or harbor where a multitude of objects may be in the water.
The system can be used in either a stand-alone capacity, or several sonar heads can be networked together to
provide surveillance over a wide area.

A single Sentinel command station can control up
to 10 sensor heads. When used as a single unit,
Sonardyne claims that Sentinel can be ready in half an
hour from deployment over the side of a vessel or into
the harbor water, and that deployment can be performed by a single individual.

Westminster International, Banbury, England, also
is developing diver-defense systems. Once a diver has
been spotted using the company’s Diver Detection

44

U.S. NAVY

Sailors assigned to Explosive Ordnance Disposal Mobile
Unit One Two, Detachment 10, prepare to guide the Cerberus swimmer-detection system into the water at Naval
Station Pascagoula, Miss., during the Gulf Coast Maritime
Domain Awareness Initiative 2005.

Sonar, its Enforcer system can be used to communicate
orders for them to vacate the area via a loudspeaker
positioned under the water. Typically, a diver will be
able to hear the command at a distance of more than
2,600 feet from the speaker.

Should the diver ignore the warning, the operator
can activate loud warning sirens and, if this is not sufficient to persuade the diver to cease their course of
action, disruptive measures can be initiated to disorientate them.

Like Sonardyne’s Sentinel system, a number of
Westminster sonar heads can be connected together
“with either fiber optics or a secure wireless Local Area
Network for command and control,” said Chris Cantell,
head of Marine Systems at Westminster International.
“With our system, the operator sees a map of the area
that they are covering. It will show on the map different projected objects like people or fish.

“When a target comes in, the system begins to collect the information and will automatically determine
what that object is. When it’s collected enough information to identify the object as a diver, a diver icon
will appear next to the target,” he said.

It is at this point that the operator can activate the
Enforcer system.

“If the intruder doesn’t obey the command, the
operator can then activate a disruptor system,” Cantell
said. “The frequencies that the disruptor system uses
are specially engineered to attack the diver and wear
them down, with the ultimate aim of forcing them to
surface. The philosophy behind the Enforcer is to carry
out psychological warfare.”